1. Field of the Invention
The invention relates to a method for manufacturing a semiconductor device utilizing a self-aligned contact process, and more particularly, to a method for manufacturing the same to provide a more highly integrated semiconductor device in which an insulating layer is formed by selectively oxidizing a polysilicon layer over regions of the device to form an insulating layer of varying thickness. The thickness of the insulating layer positioned at the contact region is minimized for easy removal during oxide etching, while sufficient thickness is maintained over the remainder of the structure to insulate the unconnected electrodes relative to each other.
2. Information Disclosure Statement
Generally, in order to selectively connect a conducting layer to selected electrodes of a plurality of electrodes which are formed in a semiconductor device, an insulating layer is deposited on the entire surface of the resulting semiconductor device. A photoresist layer is then formed on the insulating layer and, by a mask patterning process, a portion of the photoresist layer is selectively removed by lithographically etching the photoresist layer formed on the electrodes which are selected to be connected later, thereby exposing a portion of the insulating layer. Contact holes are formed by etching the exposed portion of the insulating layer. Thereafter, the remaining photoresist layer is removed and the conducting layer is deposited on the entire surface of the resulting structure, thereby selectively connecting the conducting layer through the contact holes to the selected electrodes.
However, with the prior art method, when the contact holes are formed by the lithographic etching of the insulating layer, there is a problem in that a distance must be required for a minimum misalignment tolerance required for the mask patterning process and a critical dimension loss occurred during the lithographic etching process, thereby decreasing the integrity of semiconductor device, and leakage current and parasitic capacitance can be incurred between the conducting layer and the electrode which has to be insulated therefrom due to forming the insufficient thickness of the resulting insulating layer formed therebetween.
Accordingly, it is an object of the present invention to solve the problems set forth above, and to provide a method for manufacturing a semiconductor device utilizing a self-aligned contact process, which can easily perform the contact forming process so that the integrity of semiconductor device highly increases.
The preceding objects should be construed as merely presenting a few of the more pertinent features and applications of the invention. Many other beneficial results can be obtained by applying the disclosed invention in a different manner or modifying the invention within the scope of the disclosure. Accordingly, other objects and a fuller understanding of the invention may be had by referring to both the summary of the invention and the detailed description, below, which describe the preferred embodiment in addition to the scope of the invention defined by the claims considered in conjunction with the accompanying drawings.